Development of the free-living mnematode, Turbatrix aceti, as an experimental animal for the study of aging will be continued. Further improvement of the axenic culture medium and of procedures for aging bulk cultures will be attempted. Comparison of the properties of isocitrate lyase from young and old organisms will continue. Kinetic studies, inhibition studies and affinity chromatography will be used towards helping to understand the reason for the lowered specific activity of the "old" enzyme. The enzyme from old nematodes will be investigated to see if it consists of a mixture of normal and inactive molecules, or of a single, partially active molecule. Protein turnover studies will be undertaken to see if pre-existing "normal" enzyme is converted to "inactive" enzyme, or id the latter is synthesized de novo as the organism grows older. A number of smaller molecular weight enzymes such as amylase, PEP- carboxykinase and phospoglycerate kinase will be investigated to see if they too display a loss of specific activity as the organisms age.